Ground states in the Many Interacting Worlds approach

Recently the Many-Interacting-Worlds (MIW) approach to a quantum theory without wave functions was proposed. This approach leads quite naturally to numerical integrators of the Schr\"odinger equation. It has been suggested that such integrators may feature advantages over fixed-grid methods for higher numbers of degrees of freedom. However, as yet, little is known about concrete MIW models for more than one spatial dimension and/or more than one particle. In this work we develop the MIW approach further to treat arbitrary degrees of freedom, and provide a systematic study of a corresponding numerical implementation for computing one-particle ground and excited states in one dimension, and ground states in two spatial dimensions. With this step towards the treatment of higher degrees of freedom we hope to stimulate their further study.Comment: 16 pages, 8 figure

Snare-Assisted Valve Positioning of Self-Expanding Valves for Transcatheter Aortic Valve Replacement

We describe 4 cases in which technical challenges were anticipated in delivering a self-expanding TAVR valve due to challenging aortic anatomy or a previous placed surgical aortic valve. An upfront snare strategy is described which facilitates valve centralization and atraumatic valve delivery. (Level of Difficulty: Advanced.

Mechanisms and outcome of severe mitral regulation after inoue balloon valvuloplasty

AbstractObjectives. The purpose of this study was to assess the incidence, mechanism and outcome of severe mitral regurgitation after treatment of mitral stenosis with percutaneous mitral valvuloplasty using the Inoue balloon.Background. Severe mitral regurgitation occurs in up to 15% of percutaneous balloon valvuloplasty procedures for acquired mitral stenosis. The incidence and mechanism of production of mitral regurgitation with the recently introduced single-ballon lnone technique have not been characterized.Methods. We examined the incidence, mechanism, predictors and outcome of severe mitral regurgitation after Inoue balloon valvuloplasty in 280 patients in the North American multicenter registry. Twenty-one patients who developed either clinically significant or angiographically severe regurgitation were identified, and their echocardiograms were reviewed to determine the mechanism of regurgitation. These patients were then compared with the remaining patients without severe regurgitation to identify predictors of this outcome.Results. The incidence of severe regurgitation in this study was 7.5%, and the mean grade of angiographic regurgitation in these patients increased from 0.9 ± 1.0 to 2.8 ± 0.7 (p < 0.05). The most common cause of regurgitation (43%) was rupture of clhordae tendineae to the anterior or posterior mitral leaflet. Tearing of a leaflet (usually the posterior one) occurred in 30% of patients; and no recognizable structural abnormality, with wide splitting of the commissures and a central regurgitant jet, was present in five patients (26%). All patients with definite posterior leaflet tears had heavily calcified leaflet. Patients who developed severe regurgitation had fewer balloon inflations and a higher grade of preexisting mitral regurgitation but were otherwish similar to the remaining patients without severe regurgitation. During 6-month follow-up, 71% of the patients with severe regurgitation were treated surgically; the grade of regurgitation decreased in four patients (19%), and five (24%) not required mitral valve replacement during 18 ± 5 month of follow-up.Conclusions. Severe mitral regurgitation is a relatively infrequent complication of Inoue balloon valvutoplasty and results from disruption of the valve integrity, chordal rapture and leaflet tearing. Careful balloon positioning may help avoid chordal rapture, and heavily calcified posterior lesflets may be at greater risk of tearing. Most patients who develop severe regurgitation will require nonemergency mitral valve replacement

Percutaneous Closure of an Aortic Pseudoaneurysm Due to Saphenous Vein Graft Dehiscence With an Amplatzer Vascular Plug

Tàpies Puig, Antoni; Garcés, Jordi; Sòria, EnricPla general de l'entrada a l'espai de reflexió on s'aprecia el fons un díptic de 3 per 5 metres amb la silueta campana

A Sound-Sensitive Source of Alpha Oscillations in Human Non-Primary Auditory Cortex

Copyright © 2019 Billig, Herrmann et al. The functional organization of human auditory cortex can be probed by characterizing responses to various classes of sound at different anatomical locations. Along with histological studies this approach has revealed a primary field in posteromedial Heschl\u27s gyrus (HG) with pronounced induced high-frequency (70-150 Hz) activity and short-latency responses that phase-lock to rapid transient sounds. Low-frequency neural oscillations are also relevant to stimulus processing and information flow, however, their distribution within auditory cortex has not been established. Alpha activity (7-14 Hz) in particular has been associated with processes that may differentially engage earlier versus later levels of the cortical hierarchy, including functional inhibition and the communication of sensory predictions. These theories derive largely from the study of occipitoparietal sources readily detectable in scalp electroencephalography. To characterize the anatomical basis and functional significance of less accessible temporal-lobe alpha activity we analyzed responses to sentences in seven human adults (4 female) with epilepsy who had been implanted with electrodes in superior temporal cortex. In contrast to primary cortex in posteromedial HG, a non-primary field in anterolateral HG was characterized by high spontaneous alpha activity that was strongly suppressed during auditory stimulation. Alpha-power suppression decreased with distance from anterolateral HG throughout superior temporal cortex, and was more pronounced for clear compared to degraded speech. This suppression could not be accounted for solely by a change in the slope of the power spectrum. The differential manifestation and stimulus-sensitivity of alpha oscillations across auditory fields should be accounted for in theories of their generation and function.SIGNIFICANCE STATEMENT To understand how auditory cortex is organized in support of perception, we recorded from patients implanted with electrodes for clinical reasons. This allowed measurement of activity in brain regions at different levels of sensory processing. Oscillations in the alpha range (7-14 Hz) have been associated with functions including sensory prediction and inhibition of regions handling irrelevant information, but their distribution within auditory cortex is not known. A key finding was that these oscillations dominated in one particular non-primary field, anterolateral Heschl\u27s gyrus, and were suppressed when subjects listened to sentences. These results build on our knowledge of the functional organization of auditory cortex and provide anatomical constraints on theories of the generation and function of alpha oscillations

Convergence calls: multimedia storytelling at British news websites

This article uses qualitative interviews with senior editors and managers from a selection of the UK's national online news providers to describe and analyse their current experimentation with multimedia and video storytelling. The results show that, in a period of declining newspaper readership and TV news viewing, editors are keen to embrace new technologies, which are seen as being part of the future of news. At the same time, text is still reported to be the cornerstone for news websites, leading to changes in the grammar and function of news video when used online. The economic rationale for convergence is examined and the article investigates the partnerships sites have entered into in order to be able to serve their audience with video content. In-house video is complementing syndicated content, and the authors examine the resulting developments in newsroom training and recruitment practices. The article provides journalism and interactive media scholars with case studies on the changes taking place in newsrooms as a result of the shift towards multimedia, multiplatform news consumption

Evaluation of flow after transcatheter aortic valve replacement in patients with low-flow aortic stenosis : a secondary analysis of the PARTNER randomized clinical trial

Importance: Low-flow (LF) severe aortic stenosis (AS) is an independent predictor of mortality in patients undergoing aortic valve replacement (AVR). Little is known about improvement in flow after AVR and its effects on survival. Objective: To determine whether higher flow (left-ventricular stroke volume index [LVSVI]) after transcatheter AVR (TAVR) would indicate better clinical outcomes in this at-risk population. Design, Setting, and Participants: A substudy analysis of data from the Placement of Aortic Transcatheter Valves (PARTNER) randomized clinical trial and continued-access registry was conducted. A total of 984 participants with evaluable echocardiograms and baseline LF AS (LVSVI =35 mL/m2) were included. The trial was conducted at 26 sites in the United States and Canada. Patients were stratified after TAVR into tertiles by discharge LVSVI status (severe low flow [SLF], moderate low flow [MLF], and normal flow [(NF]). The present study was conducted from May 11, 2007, to January 9, 2012, with data analysis performed from April 25, 2014, to January 21, 2016. Main Outcomes and Measures: The primary end point was all-cause mortality at 1 year. Results: Baseline characteristics of 984 patients with LF AS included mean (SD) age, 84 (7) years; 582 (59.1%) men; mean Society of Thoracic Surgeons (STS) score, 11.4% (4.0%); and mean LVSVI, 27.6 (5.0) mL/m2. The discharge LVSVI values by group were SLF, 23.1 (3.5) mL/m2; MLF, 31.7 (2.2) mL/m2; and NF, 43.1 (7.0). All-cause mortality at 1 year was SLF, 26.5%; MLF, 20.1%; and NF, 19.6% (P¿=¿.045). Mean LVSVI normalized by 6 months in the MLF (35.9 [9.3] mL/m2) and NF (38.8 [11.1] mL/m2) groups, but remained low in the SLF group at 6 months and 1 year (31.4 [8.4] and 33.0 [8.3] mL/m2], respectively) (P¿<¿.001 for all groups). Reported as multivariate hazard ratio, mortality at 1 year was higher in the SLF group compared with the other groups (1.61; 95% CI, 1.17-2.23; P¿=¿.004). In addition to SLF, sex (1.59; 95% CI, 1.18-2.13; P¿=¿.002), presence of atrial fibrillation (1.41; 95% CI, 1.06-1.87; P¿=¿.02), STS score (1.03; 95% CI, 1.01-1.06; P¿=¿.02), presence of moderate or severe mitral regurgitation at discharge (1.65; 95% CI, 1.21-2.26; P¿=¿.001), pre-TAVR mean transvalvular gradient (0.98; 95% CI, 0.97-0.99; P¿=¿.004), and effective orifice area index (1.87; 95% CI, 1.09-3.19; P¿=¿.02) were independent predictors of 1-year mortality.CONCLUSIONS AND RELEVANCE: Severe LF at discharge is associated with an increased risk of mortality following TAVR in patients with severe AS and preexisting LF. The identification of remedial causes of persistent LF after TAVR may represent an opportunity to improve the outcome of these patients

Distinct Gamma-Band Components Reflect the Short-Term Memory Maintenance of Different Sound Lateralization Angles

Oscillatory activity in human electro- or magnetoencephalogram has been related to cortical stimulus representations and their modulation by cognitive processes. Whereas previous work has focused on gamma-band activity (GBA) during attention or maintenance of representations, there is little evidence for GBA reflecting individual stimulus representations. The present study aimed at identifying stimulus-specific GBA components during auditory spatial short-term memory. A total of 28 adults were assigned to 1 of 2 groups who were presented with only right- or left-lateralized sounds, respectively. In each group, 2 sample stimuli were used which differed in their lateralization angles (15° or 45°) with respect to the midsagittal plane. Statistical probability mapping served to identify spectral amplitude differences between 15° versus 45° stimuli. Distinct GBA components were found for each sample stimulus in different sensors over parieto-occipital cortex contralateral to the side of stimulation peaking during the middle 200–300 ms of the delay phase. The differentiation between “preferred” and “nonpreferred” stimuli during the final 100 ms of the delay phase correlated with task performance. These findings suggest that the observed GBA components reflect the activity of distinct networks tuned to spatial sound features which contribute to the maintenance of task-relevant information in short-term memory